5 pin relay 24v 2 pin is the coil, and the other 3 pins have 1 only for the common terminal, 1 only for moving on (normally open), 1 only for moving off (normally closed). When the coil is energized, the contacts move.

A relay is an electrical appliance that switches on or off a control circuit according to the change of a certain input signal to realize automatic control and protection of the power drag system. The input signal can be electricity such as voltage and current, or it can be non-electricity such as speed, time, temperature and pressure. The relay is generally not used to directly control the main electrical appliance with strong signal current, but to control the main circuit through a contactor or other electrical appliances. Relays include: 1. Current relays. Second, the voltage relay. Third, the thermal relay. Fourth, the time relay. Fifth, the speed relay. There are many types of relays, and their working principles and structures are also different, but generally speaking, the relay is composed of three parts: the bearing mechanism, the intermediate mechanism and the actuator. The bearing mechanism reflects and connects to the input of the relay, and It is transmitted to the intermediate mechanism, and it is compared with the rated setting value. When the setting value is reached (excessive or insufficient), the intermediate mechanism causes the actuator to generate output, thereby turning on or off the controlled circuit.